Junction-breakdown protection semiconductor device

摘要

A junction-breakdown protection semiconductor device provides a well region which prevents the junction between a metal conductor and a diffused region from breakdown even under a high voltage or high current input. The junction-breakdown protection semiconductor device includes a metal conductor to which a high voltage is applied a semiconductor region of high impurity concentration having a conductivity type which is opposite to the conductivity type of the substrate is connected to the metal conductor through an opening in an insulating film. A second semiconductor region of the same conductivity type as the first semiconductor region is formed deeper in junction depth than the first semiconductor region under the opening in the insulator for ohmic connection on the surface of the first semiconductor region. This invention has the advantage of increased margin even with a alignment error of the ohmic connection in the fabricating process and thus provides an increased reliability of the semiconductor device.